The onetime 'X-Files' star portrays Wallis Simpson, the woman who caused a king to abdicate, in the 'Masterpiece Classic' miniseries 'Any Human Heart.

Wallis Simpson seems to be everywhere these days. She's also a character in "The King's Speech," although your portrayal of her in "Any Human Heart" was very different. She seems like less of a siren and more of a monster.

I don't know about monster. I think she gets to be a monster by the end, but you also get to see her charming side through a good part of the series.

Did you find her someone with mystique?

I did. I didn't know very much about her at all. I've been offered a couple of times before to play her, and those particular projects didn't interest me. And I really liked this story, I liked William Boyd's story. I liked [the protagonist] Logan's story. I liked its historical sweep, and I liked who she was in this, and I kind of fell for her in the process. I started to do research on her and on the two of them [her husband, the Duke of Windsor]. There isn't a great deal of footage of them, but what footage there is is incredibly compelling. And they are one person Ñ they are very much joined at the hip. There's an energy between them that's very attractive.

You played Simpson with a British accent. Did she adopt one?

She did. It's actually a mixture. I worked with a voice coach, and I have done quite a few things with British accents, and the words that she spoke with an American tinge, I tried to do the same. There were certain words phonetically that she would say that sounded very American and a lot of words that sounded very British. She moved into a British tone quite soon after moving there and spending a lot of time with David (Edward VIII). But so much of it was affected.

Can you explain her appeal?

She didn't have appeal back then. They were a mysterious international couple. The British did not like her at all. They didn't like the fact that she came and took their king away from them, and they didn't like that she was divorced, and they certainly didn't like that she was American. It wasn't even a love-hate relationship that she had; they were in the press all the time, and they were discussed as a couple, but there was an underlying animosity towards her. And yet she was stylish, and she appeared to be quite comfortable with herself and in her body and with her relationship with the prince. And the two of them were so intertwined that just watching the footage of them, they came across as extremely attractive. And they were a huge asset. If they were arriving at your party back then, every head would turn. Everybody would be talking about them. They were an international society couple.

You've done a number of period costume dramas, and I think the British do period costume dramas better than we do, even American ones. I would think that London in that respect is a better place for you. Is it?

I identify with the U.K. I grew up there [from ages 2 to 11]. I love the city of London. I love everything that it has to offer, and now my kids are half-British, so I'm very much ensconced there. But I also like the way that I'm perceived as an actor over there. People come to me with stuff that's very, very different from what I've done before. And they take risks with me, and I don't get that so much over here.

Here you're Dana Scully until death do you part?

Possibly. When they first came to me to do "Bleak House," I said, "What makes you think I can do this?" They thought that I could, and that's great. I just did something else. I did "The Crimson Petal and the White" for BBC, and it's a very large production costume drama. I play an ancient brothel owner, the mother of the main character, very decrepit and gnarly and wonderful and layers and layers of costumes and trinkets, but very, very different-looking. It was nice to be approached for it, where that wouldn't normally be the case.

Do you feel that living in London has hurt your career?

Probably it has. It was a very bold move for me to move there so soon after doing "The X-Files." It wasn't initially my intention. I was planning on going over and doing a play, and I bought a house I thought I was going to be visiting 30% to 50% of the time. And I ended up falling in love with the city and falling in love with somebody there and I just over time realized that the city suited me more. But, yeah, probably if I'd been more present here and in people's faces and out and about and in town for certain meetings, my career would have taken a different path.

But clearly that wasn't your priority.

No, it hasn't been. I've had a couple of kids - my youngest is 2 - and I feel like I'm energetic again and ready to work, so I've been coming into town and taking meetings, and there's great stuff going on.

Speaking of your children, did you name Oscar and Felix...

No. Only Americans ever ask that question. We already had the name Oscar, and we were slightly thinking about Jasper for who is now Felix, but it didn't really fit. And people would say, "Yeah, but everybody's going to say Oscar and Felix" and at a certain point we just decided that we didn't care, that we liked the rhythm of the two names together and that was more important and he felt more like a Felix than anything else.

A long time ago you vowed you'd never do television, and both you and television have changed over the years. So what's your perspective now?

I still don't watch it. I can see that there are some very intelligent and interesting things out there. I like reading, and if I want to watch something, I'll watch the news. But I don't watch television.